Yes doctors do perform to many unnecessary surgeries, although it is there job. If they have a fear of someone in a family might have something such as a disease or defect that another family has, they do things like biopsy that even though the individual may know they do not have said issue, they still state they must perform this because it is policy.
The work a doctor has to do is enormous, he has to work in shifts and sometimes they can extend up to 60 hours. 60 hours of never leaving your work place and saving lives. Therefore I highly doubt a medic would afford wasting time with unnecessary surgeries. Sometimes a medic decides to make the surgery to shorten the pain and healing time of a patient even though there the possibility of taking meds and wait. In such cases a doctor will perform a surgery only to make sure 100% that there will be no more complications which may have arrived with natural healing.